Pre-rooting is a method to hydrate and start root development in a cutting before putting it in soil. This covers stages 1 and 2 in our Rooting Overview.
Cuttings require moisture to root. Many different mediums, or no medium at all, can cause roots to develop. To increase the chances of success, however, a medium with a low PH should be used to help avoid mold and rot. Two popular choices are sphagnum and chopped peat moss. This article shows sphagnum peat moss, which is often sold as orchid soil in blocks. Chopped peat moss is the type available in large bales.
Prepare Your Cutting
First prepare your cutting using the instructions on our Rooting Overview. You can optionally wrap the top of your cutting in Parafilm. Parafilm is used for grafting and other uses and allows air to pass through, but not moisture. Parafilm can help keep the top of your cutting moist once it is potted up and before it’s root system is well established.
Warm and Moist Environment
Step 1 from the Rooting Overview is re-hydration. Re-hydration in pre-rooting is achieved through putting the prepared cutting in to an enclosed, and ideally dark, container that is moist. You can pre-hydrate your cuttings by putting the whole cutting in soaking wet moss or peat for 2-3 days. This is reported to help cuttings root more quickly. However, after 2-3 days it is important to transfer the cutting to a moist, but not wet environment. With moss this is achieved by ringing out one handful of moss at a time. The moss should be squeezed until no water runs out. Then fill a bin halfway with the moist moss, place the cutting in, and then cover the cutting with more moss.
It is a good idea to alternate the bottoms of your cuttings such that they do not all point in the same direction. This makes it easier to separate the cuttings once roots start.
Seal up your cuttings. We label each box, you can also label individual cuttings.
Place in a warm area, ideally 72F to 78F. Open the plastic bin once every day or two and fan it for a few seconds to circulate the air. Roots should begin to about 1-4 weeks. Check for roots after the first week. If there are no roots put it back and check again another week.
After your cutting has roots it is time to put it in a pot. We use 4X9 tree pots, but any plastic or ceramic pot up to about a gallon works well. We don’t recommend pots that allow moisture to pass through the walls since these tend to dry out too quickly. See our page on making soilless potting medium too.
Now that your cutting is up potted you should avoid watering as long as possible. Ideally you will not water until the cutting puts on two to three sets of leaves, though if the top 2-3 inches of soil dry out you should keep the new roots moist by watering around the edge of the pot and not directly soaking the cutting.